Apparatus for continuously monitoring air-pollution

ABSTRACT

Apparatus and process for continuously monitoring the air pollution around a manufacturing plant comprising a weather vane to sense the direction of the wind, multiple air sampling means positioned to sample air from different compass directions, a valve in line with each air sampling means, an air sample analyzer and recorder, means for transmitting a signal from the weather vane indicating the direction of the wind to the valve which is in line of the air sampling means positioned to sample air in that particular wind direction, means for drawing in an air sample from the atmosphere in the direction of the wind by sucking the air in through the air sampling means, through the valve and into the air analyzer with means in the air analyzer to determine and record the degree of a given air pollutant.

United States Patent [1 1 Smith et al.

1 Dec. 25, 1973 APPARATUS FOR CONTINUOUSLY MONITORING AIR-POLLUTION [75]Inventors: Kenneth Burton Smith; Shaul Gladstone, both of Wilmington,Del.

[73] Assignee: Argus Chemical Corp., Brooklyn,

[22] 1 Filed: Mai. 7, 1Q72 [21] Appl. No.: 232,467

US. Cl. 73/23, 73/421.5 R

Munger 73/170 R Primary Examiner-Jerry W. Myracle Attorney- Albert L.Gaz-zola [5 7] ABSTRACT Apparatus and process for continuouslymonitoring the air pollution around a manufacturing plant comprising aweather vane to sense the direction of the wind, multiple air samplingmeans positioned to sample air from different compass directions, avalve in line with each air sampling means, an air sample analyzer andrecorder, means for transmitting a signal from the weather vaneindicating the direction of the wind to the valve which is in line ofthe air sampling means positioned to sample air in that particular winddirection, means for drawing in an air sample from the atmosphere in thedirection of the wind by sucking the air in through the air samplingmeans, through the valve and into the air analyzer with means in the airanalyzer to determine and record the degree of a given air pollutant.

10 Claims, 3 Drawing Figures PATENTEU IJECZ S i975 SHEET 2 BF 2 1APPARATUS FOR CONTINUOUSLY MONITORING AIR-POLLUTION BACKGROUND OF THEINVENTION This invention relates to an apparatus and a process forcontinuously and automatically monitoring and recording the amount ofair pollutants in the atmosphere surrounding a manufacturing plant.

In the operation of a manufacturing plant, such as a plant producingchemicals, many different types of anti-air pollution devices areemployed. These devices filter, scrub or otherwise clean the gaseffluentsbefore they are let to the atmosphere.

It sometimes occurs, however, that the anti-air pollution devices willmalfunction or fail to operate properly for one reason or another.Should such a situation go undetected and exist for a sufficient periodof time it is possible that the uncleaned effluent would enter andpollute the atmosphere surrounding the plant. It is desirable,therefore, to have an independent check of the atmosphere surroundingthe plant to determine the effectiveness of the anti-air pollutiondevices in service.

Presently, independent atmospheric checks are made manually. That is, aman with an air sampling and testing kit walks to various locationsaround the plant, samples the air and tests it for pollutants. This isvery expensive, time consuming and inefficient.

Therefore, it is desirable to find an apparatus and a process forcontinuously and automatically sampling and testing the atmospheresurrounding an operating manufacturing plant, and recording the resultsfor a permanent record.

SUMMARY OF THE INVENTION Accordingly the present invention provides adevice for continuously sampling the atmosphere in the direction of thewind to monitor, detect, measure and record the amount of a givenconstituent in the atmosphere, said device comprised of:

a. multiple air sampling means positioned to sample air from differentcompass directions;

b. a valve positioned in line with each air sampling means wherein eachvalve is in a normally closed position and is activated to the openposition by an electrical signal;

c. means for detecting the wind direction;

d. means for transmitting a signal indicating the direction of the wind;

2. means for accepting the signal indicating the direction of the windand using it to operate the appropriate valve which is the valve in lineof the air sampling means positioned to sample air in the particulardirection that the wind is blowing;

f. an air sample analyzer;

g. means for drawing in an air sample from the atmosphere, in thedirection of the wind, by drawing the air in through the air samplingmeans which is positioned in the direction of the wind, through the openvalve and into the air analyzer; and

it. means in the air sample analyzer to determine the amount of a givenconstituent in the air.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is partly a cross sectionalview of the preferred embodiment of this invention, particularly showingthe weather vane, housing and microswitches, whereas the rest of thedrawing is a schematic showing the air sampling means and the air sampleanalyzer.

FIG. 2 is a view looking down into the weather vane housing showing thecam and microswitches arranged in the weathervane housing.

FIG. 3 is an electrical schematic showing the electrical circuits usedin the operation of the preferred embodiment.

DETAILS OF THE INVENTION A preferred embodiment of the apparatus of thisinvention is described below in conjunction with the drawings. Referringto FIG. 1, the apparatusfor ease of description is divided into threesystems in accordance with the function performed. System 1 is the winddirection detector and transmitting means, System 2 is the air samplingmeans and System 3 is the air sample analyzer and recorder. The workair" as used herein means the atmosphere from which a smaple is to betaken including the sample itself.

The wind direction detector means is comprised of the followingassemblage. A vane 4 having a generally trapezoidal configuration thatis attached to a circular and fiat housing cover 5 by fasteners. Twofasteners 6 and 7 are shown on one side of the vane. Two fasteners, notshown, are also used on the other side of the vane. Note that thefasteners penetrate into a block of metal 8 attached to the cover 5thereby aiding in maintaining the housing waterproof. Since vane 4 isfastened to the housing cover 5, as the wind changes direction, the vaneand housing cover rotate together.

Optionally vane 4 has a flat rectangular appendage 9 attached toincrease the surface area made available to sense the wind, therebyincreasing the sensitivity of the vane to the wind direction. It ispreferred that the vane be sensitive enough to detect at least aone-half mile per hour wind for the best results. The more sensitive thevane the more effective and accurate the pollution sensing will be.

Below the vane and housing cover is a closed end cylindrical housing 10.Inside of housing 10 is a round shaft 11 attached at one end to location12 which is the inside center of housing cover 5. The other end of shaft11 is mounted in idler bushing 13 containing preloaded ball bearings 14which bear against shaft 11. The idler bushing and bearings areconventional and can be commercially obtained from BrowningManufacturing Company, Mausville, Kentucky. Idler bushing 13 is mountedon four vertical supports and two of these supports 15 and 16 are shown.

Also included in housing 10 are four vertical supports wherein two areshown as 17 and 18 supporting flat circular plate 19. The center ofplate 19 is cut out to accommodate shaft 11. On top of plate 19 are fourvertical supports and two are shown, namely 20 and 21 supporting a flatcircular plate 22.

On top of plate 22 are mounted eight microswitches 23, 24, 25, 26, 27,28, 29 and 30. Microswitches found useful are Model No. BZ-2RQ-l8commercially available from Minneapolis Honeywell Corporation. Aboveplate 23 and keyed to shaft 11 by mechanical key 31 is cam plate 32.Stabilizing the cam plate and assisting in holding the mechanical key inplace is a round plate 33 mounted above and in contact with the cam heldin place by a set screw 34.

For a more detailed look at the top of plate 22 refer to FIG. 2. Themicroswitches are spaced in a circular configuration equidistant apartaround. the outer border of plate 22 with the microswitch plungermechani'sms pointing in on a radius towards the center of plate 22. Thecam is so designed that the high point on the cam will contact anddepress the plunger mechanism on the microswitches. At least onemicroswitch is depressed, i.e., activated at all times and when the highpoint on the cam is about centered between two microswitches (plus orminus tive degrees) both microswitches areactivated.

Since Cam 32 is keyed to shaft 11, the shaft attached to housing cover5, and the housing cover fastened to weather vane 4, any motion by theweather vane in response to the changing direction of the wind will betransmitted to cam 32 causing the cam to rotate and actuate onemicroswitch or another.

The complete assembly of wind direction detector and transmitting meansmounted on and in the generally cylindrical housing is convenientlymounted outside and exposed in a position to detect the wind such as thetop of a building. Since this assembly, in use, is always exposed to theweather it is important that it be sturdy and relatively wind andwaterproof.

In the wind direction detector and transmitting means, the sensitivityof the weather vane to the changing direction of the wind can be furtherimproved by reducing the amount of friction against shaft 11. One way ofreducing this friction is to use noncontacting microswitches for thecontacting plunger type described above. Noncontacting switches includephotoelectric switches or sonic detectors.

Referring to FIG. 1, the second system for description is the airsampling means. The air sampling means is comprised of eight samplingtubes 35, 36, 37, 38, 39, 40, 41, and 42 positioned to sample air fromdifferent compass directions, a solenoid operated valve 43, 44, 45, 46,47, 48, 49, and 50 in line with each sampling tube, and all tubesfeeding into a common manifold 51.

The sampling tubes can conveniently be made from zirconium, stainlesssteel, plastic, aluminum, or copper. A material is used that is inert tothe pollutant being sampled. Each tube is run to theoutside and thetubes are made to terminate at different locations around amanufacturing plant site preferably on the plant boundary fence. Foruniformity and a consistent reference frame, it is convenient toterminate each tube in a different compass direction, i.e., one tubesensing the north wind, another sensing the south wind, etc. In thepreferred embodiment, eight sampling tubes are used. Starting with onelocated on the north side of the plant and thereafter one every 45around the compass, i.e., northeast, east, southeast, south, etc.

Each solenoid on the valve in line with a sampling tube is electricallyconnected to a microswitch in hous-' ing 10.,These valves are normallyclosed and are activated to the open position when a signal is receivedfrom its corresponding microswitch. The solenoid valves andmicroswitches are connected in such a manner that a microswitch will beactivated to transmit a signal to the solenoid valve in line with thesampling tube that is in line with the direction of the wind. Forconvenience, the microswitches are arranged on the mounting plate 22 inthe compass direction to correspond with asampling tube that is made tosample air in that same direction. For example, when the wind is blowingfrom the north to the south this rotates the vane so that it pointssouth. In addition any pollution in the air is also directed to thesouth. Therefore, in order to take a reasonably accurate sample of theatmosphere to determine the level of air pollution a sampling tube islocated on the south side of the plant site and correspondingly the highpoint of the cam is set to point south and activate a microswitch whichis positioned on the south side of the support plate. When the switch isactivated it will open the valve in the sampling tube line which has itstermination point on the south side of the plant.

In a similar fashion each termination point of a sampling tube is madeto correspond to a different wind direction, and each sampling tube hasa valve in line electrically connected to a microswitch which isactivated by the cam attached to the vane in order to sample air in thedirection of the wind. By increasing the number of sampling tubes with acorresponding increase in the necessary valves and switches the completesystem be comes increasingly accurate. Eight sampling tubes andcorresponding apparatus are preferred since this provides practicalcoverage for the average manufacturing plant.

The third system for description is the air sample analyzer. This iscomprised of a suction tube 52 from manifold 51, a vacuum pump 53, andan analyzer 54.

When the wind is blowing in a particular direction, it rotates the vane,which rotates the cam, whereupon the high point on the cam will activatea microswitch positioned in the direction of the wind, transmitting asignal to the solenoid valve in line with the sampling tube whichterminates at a location in the direction of the wind. The vacuum pump,continuously in operation, draws air in from the atmosphere through theair sampling tube, through the valve, into the manifold, through suctiontube 52 and into the analyzer for an analysis.

The type of analyzer used will depend on the type of analysis desired.Many different types of analyzers are commercially available. Oneanalyzer found useful for determining the amount of hydrogen sulfide (H8) present in the air is manufactured by Research Appliance Company,Allison Park, Pennsylvania, and is identified as an A.l.S.I. SamplerMOdel No. F-2-Ser air and gas sampler with readout and recorder.

In brief, the analyzer works as follows. Air is drawn into the analyzerthrough the air sampling system. The sample of air is expelled on to atape chemically sensitive to H 8. The tape exhibits this sensitivity bybecoming darker with increasing amounts of H 8 in the sample. The tapeis read by passing it through a light beam wherein the opacity of thetape blocks out varying amounts of light. The amount of light passingthrough the tape is measured and converted to an electrical impulse.This impulse controls a recording needle which prints out a graphindicating the degree of the various impulses. This is an indication ofthe amount of H 8 in the air sampled, and a permanent record, thereof.

- The analyzer operates on a continuous basis. The entire system can beequipped to provide various information such as, a time sequence recordof the sampling, the particular sampling valve through which the samplewas taken, thereby indicating the direction of the wind and the degreeof pollution of H 8 in the air. Various types of analyzers are availableand they can be incorporated to detect various pollutants such as carbonmonoxide, carbon dioxide, nitrogen dioxide, and mercury.

A particularly useful attachment is an event recorder. An event recorderis commercially available as Model 292-8 manufactured by RustrakInstrument Division of Gulton Industries, Inc., Manchester, New Hamphsire. This recorder has eight channels each one attached to a differentmicro switch. When the microswitch is activated the recorder will recordthe particular microswitch that is activated, thereby indicating thedirection of the wind, the length of time activated and the time of day.This coupled with the record of time and amount of pollution in the airgives a very accurate and complete record of the amount of pollutionemanating from a particular plant.

The electrical aspects of this invention will now be discussed withparticular reference to the electrical schematic of FIG. 3. To put theunit in operation, master switch 55 is closed. As weather vane 4 rotatesin accordance with the changing direction of the wind, shaft 1 1attached to the vane rotates the cam which is keyed to the shaft. As thecam rotates, the high point on the cam depresses a plunger activating aswitch. These switches are represented by numerals 56, 57, 58, 59, 60,61, 62, and 63. Each microswitch is electrically connected to thesolenoid portion of the solenoid operated valves through a time delayrelay. These solenoids are represented by numerals 64, 65, 66, 67, 68,69, 70, and 71. The time delay relays are represented by numerals 72,73, 74, 75, 76, 77, 78, and 79. As the solenoid is activated, it opens anormally closed valve permitting an air sample to be taken.

When a microswitch is deactivated, i.e., the high point on the cam movesoff the switch plunger, thereby de-energizing the solenoid. Pneumaticbellows in the solenoid, however, keep the time delay relay contactsclosed for 60 seconds thereby holding the valve open for 60 secondsafter its corresponding solenoid is deactivated. Thereafter, therelaycontacts are open afidth? valve will return to its normally closedposition. This time delay is necessary to keep the valves from openingand closing instantaneously as the weather vane swings with the changingdirection of the wind. Otherwise the valves would be worn within arelatively short period of time.

This apparatus is particularly valuable in continuously monitoring thedegree of air pollution. When used on a plant site it provides a meansfor monitoring the degree of pollution emanating from a particularplant. This will provide a means for both plant managers and Governmentagencies to continuously monitor the air pollution caused by aparticular plant.

We claim:

1. A device for continuously sampling the atmosphere in the direction ofthe wind to monitor, detect and measure the amount of a givenconstituent in the atmosphere, said device comprised of:

a. multiple air sampling means positioned to sample air from differentcompass directions;

b. a valve positioned in line with each air sampling means wherein eachvalve is in a normally closed position and is activated to the openposition by an electrical signal;

c. means for detecting the wind direction;

d. means for transmitting a signal indicating the direction of the wind;

means for accepting the signal indicating the direction of the wind andusing this signal to operate the appropriate valve to the open positionwhich is the valve in line of the air sampling means positioned tosample air in the particular direction that the wind is blowing;

an air sample analyzer;

means for drawing in an air sample from the atmosphere, in the directionof the wind, by drawing the air in through the air sampling means whichis positioned in the direction of the wind, through the open valve andinto the air analyzer; and

h. means in the air sample analyzer to determine the amount of a givenconstituent in the air.

2. The apparatus of claim 1 including the additional means for recordingthe amount of the given constituent analyzed.

3. The apparatus of claim 2 including an event recorder means forrecording the length of time and the compass direction of sampling.

4. The apparatus of claim 2 wherein the means for detecting the winddirection is a weather vane.

5. The apparatus of claim 4 wherein the means for transmitting a signalindicating the direction of the wind is a cam fixed 'to rotate with theweather vane and multiple microswitching means spaced in a circularconfiguration equidistant apart around the cam wherein the spacedrelationship is such that the cam will activate a different microswitchas the cam rotates with the rotation of the weather vane.

6. The apparatus of claim 5 wherein the cam is designed so that when thecam is about centered between two microswitches, the microswitches nextadjacent the cam on either side are both activated.

7. The apparatus of claim 5 wherein the microswitching means is asonic-electric operated microswitch.

8. The apparatus of claim 5 wherein the microswitching means is aphoto-electric operated microswitch.

9. The apparatus of claim 5 wherein the microswitching means is amechanically operated microswitch.

10. The apparatus of claim 9 wherein the multiple air sampling means arehollow tubes, the means for accepting the signal indicating thedirection of the wind and using this signal to operate the appropriatevalve is a solenoid, and the means for drawing in an air sample from theatmosphere is a vacuum pump.

1. A device for continuously sampling the atmosphere in the direction ofthe wind to monitor, detect and measure the amount of a givenconstituent in the atmosphere, said device comprised of: a. multiple airsampling means positioned to sample air from different compassdirections; b. a valve positioned in line with each air sampling meanswherein each valve is in a normally closed position and is activated tothe open position by an electrical signal; c. means for detecting thewind direction; d. means for transmitting a signal indicating thedirection of the wind; e. means for accepting the signal indicating thedirection of the wind and using this signal to operate the appropriatevalve to the open position which is the valve in line of the airsampling means positioned to sample air in the particular direction thatthe wind is blowing; f. an air sample analyzer; g. means for drawing inan air sample from the atmosphere, in the direction of the wind, bydrawing the air in through the air sampling means which is positioned inthe direction of the wind, through the open valve and into the airanalyzer; and h. means in the air sample analyzer to determine theamount of a given constituent in the air.
 2. The apparatus of claim 1including the additional means for recording the amount of the givenconstituent analyzed.
 3. The apparatus of claim 2 including an eventrecorder means for recording the length of time and the compassdirection of sampling.
 4. The apparatus of claim 2 wherein the means fordetecting the wind direction is a weather vane.
 5. The apparatus ofclaim 4 wherein the means for transmitting a signal indicating thedirection of the wind is a cam fixed to rotate with the weather vane andmultiple microswitching means spaced in a circular configurationequidistant apart around the cam wherein the spaced relationship is suchthat the cam will activate a different microswitch as the cam rotateswith the rotation of the weather vane.
 6. The apparatus of claim 5wherein the cam is designed so that when the cam is about centeredbetween two microswitches, the microswitches next adjacent the cam oneither side are both activated.
 7. The apparatus of claim 5 wherein themicroswitching means is a sonic-electric operated microswitch.
 8. Theapparatus of claim 5 wherein the microswitching means is aphoto-electric operated microswitch.
 9. The apparatus of claim 5 whereinthe microswitching means is a mechanically operated microswitch.
 10. ThEapparatus of claim 9 wherein the multiple air sampling means are hollowtubes, the means for accepting the signal indicating the direction ofthe wind and using this signal to operate the appropriate valve is asolenoid, and the means for drawing in an air sample from the atmosphereis a vacuum pump.